U.S. patent application number 16/311408 was filed with the patent office on 2019-11-07 for gel composition and production method therefor.
The applicant listed for this patent is DSP Gokyo Food & Chemical Co., Ltd.. Invention is credited to Hiroshi Egawa, Akira Tabuchi.
Application Number | 20190338081 16/311408 |
Document ID | / |
Family ID | 60783917 |
Filed Date | 2019-11-07 |
![](/patent/app/20190338081/US20190338081A1-20191107-D00001.png)
United States Patent
Application |
20190338081 |
Kind Code |
A1 |
Tabuchi; Akira ; et
al. |
November 7, 2019 |
GEL COMPOSITION AND PRODUCTION METHOD THEREFOR
Abstract
Provided is a production method for a gel composition including
steps (1) to (3) mentioned below: step (1) of mixing at room
temperature a partial degradation product of the galactose moiety
of galactoxyloglucan and an aqueous solvent to obtain a mixture;
step (2) of cooling or freezing the mixture obtained in step (1);
and step (3) of gelling the mixture cooled or frozen in step (2) by
heating to obtain a gel composition that includes the
galactose-partial degradation product.
Inventors: |
Tabuchi; Akira; (Osaka,
JP) ; Egawa; Hiroshi; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DSP Gokyo Food & Chemical Co., Ltd. |
Osaka |
|
JP |
|
|
Family ID: |
60783917 |
Appl. No.: |
16/311408 |
Filed: |
June 24, 2016 |
PCT Filed: |
June 24, 2016 |
PCT NO: |
PCT/JP2016/068891 |
371 Date: |
December 19, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J 3/075 20130101;
B01J 13/0052 20130101; C08B 37/0087 20130101 |
International
Class: |
C08J 3/075 20060101
C08J003/075; C08B 37/00 20060101 C08B037/00 |
Claims
1. A production method for a gel composition, comprising steps (1)
to (3) mentioned below: step (1) of mixing at room temperature a
partial degradation product of the galactose moiety of
galactoxyloglucan and an aqueous solvent to obtain a mixture; step
(2) of cooling or freezing the mixture obtained in step (1); and
step (3) of gelling the mixture cooled or frozen in step (2) by
heating to obtain a gel composition that comprises the
galactose-partial degradation product.
2. The production method for the gel composition according to claim
1, wherein, in step (1), the galactose-partial degradation product
and the aqueous solvent are mixed at 18 to 30.degree. C.
3. The production method for the gel composition according to claim
1, wherein, in step (1), 30 to 55% of the galactose moiety is
degraded in the galactose-partial degradation product.
4. The production method for the gel composition according to claim
1, wherein, in step (1), 0.05 to 20 mass % of the galactose-partial
degradation product is included in the mixture.
5. The production method for the gel composition according to claim
1, wherein, in step (2), the mixture obtained in step (1) is cooled
or frozen to -25 to 10.degree. C.
6. The production method for the gel composition according to claim
1, wherein the aqueous solvent is water or salt aqueous
solution.
7. A gel composition comprising a partial degradation product of
the galactose moiety of galactoxyloglucan obtained by the method
according to claim 1.
Description
FIELD
[0001] The present invention relates to a gel composition and
production method therefor.
BACKGROUND
[0002] Conventionally, galactoxyloglucan is known as a natural
polysaccharide. Galactoxyloglucan includes glucose, xylose, and
galactose as constituent sugars, a main chain of which has
.beta.-1,4-bonded glucose, and a side chain of which has xylose and
galactose bonded to the xylose. Galactoxyloglucan itself is not
usually gelled, while being gelled in the presence of saccharide,
ion, or alcohol.
[0003] Meanwhile, there has been proposed a partial degradation
product of the galactose moiety of galactoxyloglucan, which is
obtained by partially degrading (partial degradation) to remove a
galactose moiety constituting a part of the side chain of
galactoxyloglucan using refined .beta.-galactosidase derived from
microorganisms (hereinafter also referred to simply as
"galactose-partial degradation product") (see Patent Literatures 1
and 2). When galactose-partial degradation product is mixed with an
aqueous solvent, a mixture thereof shows a thermal behavior having
a reversed relationship with the thermal behavior of the
galactoxyloglucan. Specifically, the galactose-partial degradation
product is gelled when heated and solated when cooled so that it
shows a thermal behavior in this sol/gel change is reversible. Such
a thermal behavior is called reverse thermal gelation
characteristics. The galactose-partial degradation product is
derived from natural polysaccharides and is not subjected to
chemical modification (addition), and therefore is harmless to
humans and the environment. Therefore, gel compositions produced
using the galactose-partial degradation product can be widely used
in foods, cosmetics, pharmaceutical formulations and the like.
There have been proposed, as a production method for a gel
composition including a galactose-partial degradation product of
this kind, a method for producing a gel composition by mixing a
cooled aqueous solvent with a galactose-partial degradation product
to allow the galactose-partial degradation product to dissolve in
the aqueous solvent, and gelling the dissolved solution by heating
(see Patent Literatures 1 and 2).
CITATION LIST
Patent Literature
[0004] Patent Literature 1: JP 118-283305
[0005] Patent Literature 2: International Publication
WO97/29777
SUMMARY
Technical Problem
[0006] In general, it is said that an aqueous solvent is preferably
mixed with polysaccharides in order to prevent formation of
undissolved lumps at the time of contact of the aqueous solvent
with the polysaccharides, in order to easily produce a gel
composition including polysaccharides. This is because a powdery
solid matter (nonhydrate product) resulting from nonhydrated
polysaccharides remains in the produced gel composition, which
causes deterioration in quality. Also, a long time and much labor
are needed to dissolve polysaccharides which have become
undissolved lumps by completely hydrating deep inside the
polysaccharides.
[0007] In this regard, according to the methods of Patent
Literatures 1 and 2, a method employed is that, when producing a
gel composition using a galactose-partial degradation product, the
galactose-partial degradation product is mixed with a cooled
aqueous solvent to allow themselves to be dissolved. However, these
methods necessitate cooling an aqueous solvent followed by mixing
of the galactose-partial degradation product, which takes a lot of
time and labor for preparation. These methods also cause excessive
viscosity of the mixture, which may cause difficulty in handling
when it is transferred to a desirable container and is gelled by
heating. Also, these methods may cause a difficulty in filling a
desirable container with a sufficient amount of the mixture or
cause air bubbles to be easily entrained in the mixture during
preparation or filling of a solution. Thus, it is hard to say that
a gel composition can be easily produced by these methods of Patent
Literatures 1 and 2.
[0008] In view of the above circumstances, it is an object of the
present invention to provide a production method that is capable of
easily producing the gel composition including a partial
degradation product of the galactose moiety of galactoxyloglucan,
and a gel composition produced by the production method.
Solution to Problem
[0009] In order to achieve the aforementioned object, the inventors
of the subject application have diligently studied as mentioned
below. It is generally known that, when a polysaccharide is mixed
with an aqueous solvent, water in the aqueous solvent causes the
polysaccharide to first hydrate and swell, and when the hydration
and swelling further proceeds, the polysaccharide dissolves. As a
result of taking into account this fact and the methods of Patent
Literatures 1 and 2, it has been found that, since the methods of
Patent Literatures 1 and 2 include a step of dissolving a
galactose-partial degradation product by being mixed with a cooled
aqueous solvent, the dissolved solution has a relatively high
viscosity, which results in difficulty in handling of the dissolved
solution. Also, as the temperature of the aqueous solvent is
lowered by cooling, the time required for the galactose-partial
degradation product to come into the hydration and swollen state,
further the time required for it to convert from the hydration and
swollen state into the dissolved state are shortened. Because of
this, it was found that, in the methods of Patent Literatures 1 and
2, viscosity develops at an early stage, and therefore, the
dissolved solution must be forcibly stirred with a relatively
strong force in order to homogeneously disperse the
galactose-partial degradation product in the aqueous solvent. As a
result of the diligent studies based on these findings, the
inventors of the subject application have found that, by mixing the
aqueous solvent and the galactose-partial degradation product at
room temperature, the galactose-partial degradation product can be
dispersed in an aqueous solvent without occurrence of undissolved
lumps in a mixture. Such mixing at room temperature causes the
galactose-partial degradation product to be easily brought into a
state where it is almost undissolved in the aqueous solvent, which
results in producing a mixture having a low viscosity. Further,
cooling or freezing the mixture having such a low viscosity causes
the galactose-partial degradation product to be easily brought into
a state where it is not dissolved but is easy to hydrate and swell
in a high viscous state, which results in producing a mixture
having a high viscosity. Further, there is no need to cool the
aqueous solvent in advance, by which time and labor for it is
eliminated. It has also been found that, even if a mixture with the
galactose-partial degradation product almost hydrated and swelled
therein is heated, the mixture can be gelled and hence a gel
composition can be produced. Thus, the present invention have been
achieved.
[0010] Specifically, according to the present invention, there is
provided a production method for a gel composition, including steps
(1) to (3) mentioned below:
[0011] step (1) of mixing at room temperature a partial degradation
product of the galactose moiety of galactoxyloglucan and an aqueous
solvent to obtain a mixture;
[0012] step (2) of cooling or freezing the mixture obtained in step
(1); and
[0013] step (3) of gelling the mixture cooled or frozen in step (2)
by heating to obtain a gel composition that includes the
galactose-partial degradation product.
[0014] The "room temperature" herein means a temperature within a
range of from 15 to 35.degree. C. "Mixing at room temperature"
means mixing with the aqueous solvent being at room temperature.
The state "cooled" means a state where the mixture of the aqueous
solvent and the galactose-partial degradation product is not
solidified by lowering the temperature, and also means the state
where liquefied portions and solidified portions (i.e., frozen
portions) are both present. The state "frozen" means a state where
the mixture of the aqueous solvent and the galactose-partial
degradation product is solidified by lowering the temperature.
[0015] Meanwhile, in the present description, the "dispersed" state
of the galactose-partial degradation product means a state where,
while the aqueous solvent penetrates galactose-partial degradation
product which is entirely in powder form, it is present in the
aqueous solvent with little formation of a highly viscous
(adhesive) layer on the surface layer. The state "hydrated and
swollen" means a state where the galactose-partial degradation
product which is entirely in powder form fully absorbs the aqueous
solvent, and the galactose-partial degradation product as a whole
is kept in a highly viscous state. The state "dissolved" means a
state where polysaccharide molecule chains are detached from the
highly viscous surface layer and disperse from the surface layer
into the solvent. The state "undissolved lumps" means a state where
the galactose-partial degradation product in powder form as a whole
is lumped or such undissolved lumps are further form a group,
resulting from that the galactose-partial degradation product in
powder form which is in aggregated form (forming a aggregated
product) comes into contact with water, allowing only the outer
layer of the aggregated product having an air layer contained
therein to form a highly viscous state by the contact with water,
and thereby making the aqueous solvent less penetrate the inside of
the aggregated product.
[0016] In step (1) of the production method for the gel composition
having the above construction, the galactose-partial degradation
product and the aqueous solvent are preferably mixed at 18 to
30.degree. C.
[0017] In step (1) of the production method for the gel composition
having the above construction, 30 to 55% of the galactose moiety is
preferably degraded in the galactose-partial degradation
product.
[0018] In step (2) of the production method for the gel composition
having the above construction, the mixture obtained in step (1) is
preferably cooled or frozen to -25 to 10.degree. C.
[0019] In step (1) of the production method for the gel composition
having the above construction, 0.05 to 20 mass % of the
galactose-partial degradation product is preferably included in the
mixture.
[0020] In the production method for the gel composition having the
above construction, the aqueous solvent preferably includes water
or salt aqueous solution.
[0021] The gel composition according to the present invention
includes a partial degradation product of the galactose moiety of
galactoxyloglucan obtained by the aforementioned production method
for the gel composition.
BRIEF DESCRIPTION OF DRAWINGS
[0022] FIG. 1 is a graph showing a relationship between time and
viscosity after a galactose-partial degradation product is
dispersed in water at room temperature.
DESCRIPTION OF EMBODIMENTS
[0023] Hereinafter, embodiments of a production method for a gel
composition and a gel composition produced by the production method
according to the present invention will be described.
[0024] A production method for the gel composition of this
embodiment includes steps (1) to (3) mentioned below:
[0025] step (1) of mixing at room temperature a partial degradation
product of the galactose moiety of galactoxyloglucan and an aqueous
solvent to obtain a mixture;
[0026] step (2) of cooling or freezing the mixture obtained in step
(1); and
[0027] step (3) of gelling the mixture cooled or frozen in step (2)
by heating to obtain a gel composition that includes the
galactose-partial degradation product.
[0028] The partial degradation product of the galactose moiety of
galactoxyloglucan used for the production method of this embodiment
means a substance, which is obtained by partially dissolving to
remove the galactose moiety on the side chain of galactoxyloglucan,
and the partial degradation product of the galactose moiety of
galactoxyloglucan hereinafter may be abbreviated as the
galactose-partial degradation product. Galactoxyloglucan means
galactoxyloglucan (complete galactoxyloglucan) of which the
galactose moiety on the side chain is not removed by partial
degradation with later-described enzyme treatment. This complete
galactoxyloglucan may also be referred to as native
galactoxyloglucan.
[0029] Galactoxyloglucan is a constituent of a cell wall (a primary
wall) of a higher plant such as dicotyledon and monocotyledon, and
exists as a storage polysaccharide of some plant seeds.
Galactoxyloglucan includes glucose, xylose, and galactose as
constituent sugars, a main chain of which has .beta.-1,4-bonded
glucose, and a side chain of which has xylose and galactose bonded
to the xylose. Galactoxyloglucan itself is not usually gelled,
while being gelled in the presence of saccharide, ion, or
alcohol.
[0030] Galactoxyloglucan may be galactoxyloglucan derived from any
plants and obtainable from, for example, seeds of tamarind, jatoba,
and nasturtium, cereal such as soybean, mung bean, kidney bean,
rice, and barley, or skin of fruits such as apple. A preferable one
is galactoxyloglucan derived from leguminous-plants tamarind seed
because of the easiest availability and the large content of
galactoxyloglucan. A commercially available one can be employed as
such galactoxyloglucan.
[0031] The galactose-partial degradation product used for the
production method of this embodiment is produced by the following
production methods, for example. Specifically, the
galactoxyloglucan derived from tamarind seed is maintained at
55.degree. C. and then adjusted to pH 6 with trisodium citrate,
followed by addition of .beta.-galactosidase thereto, to react at
50 to 55.degree. C. for 16 hours, while being stirred.
Subsequently, after the enzyme is deactivated by heating at
95.degree. C. for 30 minutes, the obtained product is returned to
room temperature, followed by addition of an equal volume of
ethanol thereto, to be left standing for 1 hour. Precipitates which
were obtained after being left standing are collected by way of
suction filtration and dried with a ventilation drier, and
thereafter the precipitates are pulverized to thereby produce a
galactose-partial degradation product.
[0032] .beta.-galactosidase to be used may be any product derived
from plants or microorganisms, but a preferable one is enzyme
derived from microorganisms such as Aspergillus oryzae and Bacillus
circulans, or enzyme present in a galactoxyloglucan-containing
seed. A commercially available one can be employed as such a
.beta.-galactosidase.
[0033] In the enzyme reaction with this .beta.-galactosidase, the
galactose moiety on the side chain of the galactoxyloglucan is
partially removed with the progress of reaction, and when the
galactose removal ratio reaches about 30%, the reaction solution is
rapidly thickened in viscosity and gelled. When the galactose
removal ratio is in the range of 30 to 55%, the galactose-partial
degradation product has reverse thermal gelation characteristics,
whereby it is gelled when heated and solated when cooled. The
galactose-partial degradation product tends to be not gelled with
the galactose removal ratio of less than 30%, while
galactose-partial degradation product tends to form an excessively
hard gel with the removal ratio over 55% (see JP 118-283305 and
International Publication WO97/29777).
[0034] In consideration of this, it is preferable to use the
aforementioned galactose-partial degradation product in which 30 to
55% of a galactose moiety is degraded. By setting the removal ratio
within this range, it is possible to produce a gel composition that
is not excessively hard, while allowing it to exhibit sufficient
gelation characteristics by heating. This makes it easier to allow
the galactose-partial degradation product to exhibit the reverse
thermal gelation characteristics whereby it is fully gelled when
heated and fully solated when cooled in a reversible manner.
[0035] The aforementioned galactose-partial degradation product in
which 30 to 55% of a galactose moiety is degraded is produced from
galactoxyloglucan in which 30 to 55% of a galactose moiety is
degraded as mentioned above. Galactoxyloglucan usually includes
about 37% of a side-chain xylose and about 17% of a side-chain
galactose (see Gidley, et al., Carbohydrate Research), 214 (1991),
pp. 219 -314). Therefore, it is calculated that the
galactose-partial degradation product in which 30 to 55% of a
galactose moiety is degraded includes 39 to 41% of a side-chain
xylose and 8 to 12% of a side-chain galactose. The ratio of
degradation of a galactose moiety (that is, the galactose removal
ratio) can be calculated by measuring an amount of
galactoxyloglucan oligosaccharides generated by cellulase
degradation of the obtained partial degradation product with high
performance liquid chromatography (HPLC) (amino column).
[0036] In step (1) in the production method for this embodiment,
the galactose-partial degradation product and the aqueous solvent
are mixed at room temperature to thereby obtain a mixture thereof.
More specifically, a dispersion liquid (i.e., suspension liquid) as
a mixture in which the galactose-partial degradation product has
been dispersed in the aqueous solvent can be obtained by mixing the
galactose-partial degradation product with the aqueous solvent at
room temperature.
[0037] As mentioned above, as the temperature of the aqueous
solvent is lowered by cooling, the time required for the
galactose-partial degradation product to reach the hydration and
swollen state and the time required for the galactose-partial
degradation product to be transformed from the hydration and
swollen state into the dissolved state are shortened. In such a
state where the time required for the galactose-partial degradation
product to reach the dissolved state is relatively short, a
relatively strong stirring force is required in order to disperse
the galactose-partial degradation product in the aqueous solvent as
homogeneously as possible. That is, a relatively strong stirring
force is required in order to dissolve the galactose-partial
degradation product in the cooled aqueous solvent as homogeneously
as possible.
[0038] On the other hand, the time required for the
galactose-partial degradation product to reach the hydration and
swollen state in the aqueous solvent at room temperature and the
time required for the galactose-partial degradation product to
reach the dissolved state are much longer than those in the case of
using the cooled aqueous solvent, and therefore, the
galactose-partial degradation product hardly dissolves even when
the stirring is performed with the same force as that mentioned
above. Accordingly, the occurrence of undissolved lumps caused by
the galactose-partial degradation product can be suppressed by
mixing the galactose-partial degradation product with the aqueous
solvent at room temperature in step (1).
[0039] A gathered powder seems to occur in a dispersion liquid
during mixing of the galactose-partial degradation product with an
aqueous solvent. However, this is not an undissolved lump and
therefore the galactose-partial degradation product can be easily
dispersed almost completely by lightly crumbling the gathering with
spatula (spatel) or the like. The operation of "crumbling" herein
means bringing a gathered substance back to the form or unit before
it is gathered, and means an operation entirely different from
stirring to be carried out generally for dissolving a
substance.
[0040] The temperature of the aqueous solvent during mixing the
aqueous solvent and the galactose-partial degradation product is
not particularly limited, provided that it is at room temperature,
but the temperature to be employed is preferably 18 to 30.degree.
C., more preferably 18 to 28.degree. C. By mixing at 18.degree. C.
or higher, it is possible to disperse the galactose-partial
degradation product in the aqueous solvent, while further avoiding
occurrence of undissolved lumps. Thereby, it is possible to further
suppress increase in viscosity caused, for example, when the
galactose-partial degradation product has been dissolved. Thus, it
is possible to suppress deterioration of workability. Further, as a
result of the mixing at 30.degree. C. or lower, the
galactose-partial degradation product can be dispersed in the
aqueous solvent under the ordinary environment at room temperature
without need for special conditions such as heating, thereby
enabling these steps to be performed by a simple operation. The
aforementioned mixing may be performed while the heating is
performed. Thus, it is possible to suppress deterioration of
workability by mixing the galactose-partial degradation product and
the aqueous solvent at 18 to 30.degree. C.
[0041] The time for mixing the aqueous solvent with the
galactose-partial degradation product is not particularly limited
and may be appropriately set when considering that the
galactose-partial degradation product has a very good affinity to
the aqueous solvent at the aforementioned temperature. The mixing
time to be employed is, for example, 5 minutes to 1 hour, and
preferably 10 minutes to 30 minutes. Setting the mixing time at 1
hour or less is advantageous in that the operation can be finished
earlier and the workability can be improved.
[0042] The content of the galactose-partial degradation product in
the aqueous solvent is not particularly limited and may be
appropriately set. For example, the content may be suitably set
according to the desired gel characteristics of the gel composition
to be obtained. In view of this aspect, the content of the
galactose-partial degradation product in the mixture is preferably
0.05 to 20 mass %, more preferably 1 to 10 mass %, still more
preferably 3 to 10 mass %, and further preferably 3 to 5 mass %,
for example. With the content of the galactose-partial degradation
product of 0.05 mass % or more in the mixture, it is possible to
more securely gel the mixture. Further, the galactose-partial
degradation product content of 3 mass % or more is preferable when
considering that a water layer may be not easily formed on the
surface of the gel. Meanwhile, with the content of
galactose-partial degradation product of 20 mass % or less, it is
possible to allow a moderate amount of water to be retained in the
gel so that a gel composition capable of exhibiting desired gel
characteristics can be produced. Further, a gel composition capable
of further exhibiting desired gel characteristics can be produced
by mixing together the respective components of the mixture within
a shallow (small depth) container (that is, in a state where the
depth of the mixture is made small). When the concentration of the
galactose-partial degradation product is low, water that could not
contribute to gelation may form a layer on the upper side of the
gel composition and the rest below it may form a gelled layer by
heating the later-described cooled or frozen mixture. In this case,
it is also possible to obtain the gel layer below the water layer
(separated water) as a gel composition by removing the water layer
(separated water) on the upper side. That is, it is possible to
produce a gel composition by concentration of the later-described
cooled or frozen mixture. When considering that the water layer is
thus removed depending on the concentration of the
galactose-partial degradation product, the concentration of the
galactose-partial degradation product in the produced gel
composition (when the water layer is removed, the gel composition
after the removal, and when the water layer does not occur, the gel
composition as produced) is preferably 1 to 20 weight %, more
preferably 1 to 10 weight %, and still more preferably 2 to 5
weight %.
[0043] The aqueous solvent is not particularly limited provided
that it is a solvent containing water; however, water, salt aqueous
solution, and the like can be mentioned, for example. As the salt
aqueous solution, sodium salt aqueous solution, calcium salt
aqueous solution, buffer solution, and the like can be mentioned.
As the buffer solution, a phosphate buffer solution, a citrate
buffer solution, and the like of pH 4 to 7 can be mentioned.
[0044] According to step (1), it is also possible to obtain the gel
composition as a molded article formed into a desired shape by
transferring the mixture to a mold or the like having a desired
shape before cooling or freezing in step (2).
[0045] In step (2), the mixture obtained in step (1) is cooled or
frozen. More specifically, a hydrated swollen product in which the
galactose-partial degradation product is hydrated and swollen in
the aqueous solvent is obtained by cooling or freezing the
dispersion liquid obtained in step (1). Examples of the hydrated
swollen product include a hydrated swollen product in liquid form
that has been cooled but not frozen and a hydrated swollen product
in solid form that has been frozen. In step (2), the aqueous
solvent may include a dissolved product resulting from partial
dissolving of the galactose-partial degradation product.
[0046] According to step (2), the galactose-partial degradation
product dispersed in the aqueous solvent in step (1) can be
hydrated and swollen with water in the aqueous solvent by cooling
or freezing the mixture of the aqueous solvent and the
galactose-partial degradation product. Since hydration and swelling
can be thus produced, the development of viscosity can be
relatively delayed, and thereby the galactose-partial degradation
product can be dispersed in the aqueous solvent without need for
forcible stirring with a relatively strong force as conventionally
needed. Thus, the production method is simplified because the need
for forcible stirring can be eliminated. In step (2), forcible
stirring is not necessarily eliminated, but when forcible stirring
is performed, the hydration and swelling of the galactose-partial
degradation product can be more quickly produced than in the case
of skipping the forcible stirring.
[0047] In the cooling or the freezing, the degree by which the
temperature of the mixture is to be lowered is not particularly
limited and may be appropriately set, provided that the
galactose-partial degradation product in the mixture (dispersion
liquid) obtained in step (1) can be hydrated and swollen. As the
degree by which the temperature of the mixture is lowered is
greater, the galactose-partial degradation product tends to be more
easily hydrated and swollen, but on the other hand, the hydration
and swelling tends to excessively progress to thereby cause the
viscosity to be easily developed. In view of this aspect, it is
preferable to cool or freeze the mixture obtained in step (1) to
-25 to 10.degree. C., for example. When the upper limit of the
range of temperature, to which the temperature of the mixture is
lowered, is set at 10.degree. C. or lower, the galactose-partial
degradation product is easily hydrated and swollen. The upper limit
is more preferably 5.degree. C. or lower, still more preferably
1.degree. C. or lower when considering that the hydration and
swelling of the galactose-partial degradation product can be
produced at such a temperature. On the other hand, when the lower
limit of the range of temperature to which the temperature of the
mixture is lowered is set at -25.degree. C., excessive progress of
hydration and swelling is suppressed, thereby making it hard for
the viscosity to develop.
[0048] In step (3), the gel composition including the
galactose-partial degradation product can be obtained by heating
the mixture cooled or frozen in step (2), thereby gelling the same.
More specifically, in step (3), the gel composition including the
galactose-partial degradation product is obtained by heating the
hydrated swollen product obtained in step (2), thereby gelling the
same.
[0049] In the heating, the degree by which the temperature of the
cooled or frozen mixture (hydrated swollen product) obtained in
step (2) is to be raised is not particularly limited and may be
appropriately set, provided that the mixture is raised to a
temperature at which the mixture can be fully gelled. As the degree
by which the temperature of the mixture is raised is greater, the
gel strength can be increased, but on the other hand, unnecessary
heating operation is increased and hence the workability tends to
be deteriorated. In view of this aspect, it is preferable to raise
the temperature of the cooled or frozen mixture to 25 to 60.degree.
C., for example. The gel strength can be sufficiently increased by
setting the lower limit of the range of temperature, to which the
temperature of mixture is raised, at 25.degree. C. The lower limit
is more preferably 40.degree. C. or higher when considering that
the gel strength can be more sufficiently increased. Meanwhile,
when the upper limit of the range of temperature, to which the
temperature of mixture is raised, is 60.degree. C. or lower,
unnecessary heating operation can be suppressed and hence the
workability is suppressed from being deteriorated. The upper limit
is still more preferably 50.degree. C. or lower from the aspect of
suppressing unnecessary heating operations.
[0050] The gel composition of this embodiment is a gel composition
including a galactose-partial degradation product obtained by the
production method of this embodiment. The gel composition of this
embodiment preferably has heat resistance and water resistance.
[0051] As mentioned above, the production method for the gel
composition of this embodiment includes steps (1) to (3) mentioned
below:
[0052] step (1) of mixing at room temperature a partial degradation
product of the galactose moiety of galactoxyloglucan and an aqueous
solvent to obtain a mixture;
[0053] step (2) of cooling or freezing the mixture obtained in step
(1); and
[0054] step (3) of gelling the mixture cooled or frozen in step (2)
by heating to obtain a gel composition that includes the
galactose-partial degradation product.
[0055] With the production method for the gel composition of this
embodiment, in step (1), the partial degradation product of the
galactose moiety of galactoxyloglucan is mixed with the aqueous
solvent at room temperature so that the galactose-partial
degradation product can be dispersed in the aqueous solvent without
occurrence of undissolved lumps in the mixture. In step (2), the
mixture obtained in step (1) is cooled or frozen, and thereby the
galactose-partial degradation product can be hydrated and swollen
in the aqueous solvent. At this time, it is possible to easily
bring the galactose-partial degradation product into not the
dissolved state but the hydrated swollen state. Thereby, it is
possible to lower the viscosity of the mixture and allow the
mixture to be a hydrated swollen product having high viscosity by
cooling or freezing the mixture. Further, since the development of
viscosity can be relatively delayed, the galactose-partial
degradation product can be fully dispersed in the aqueous solvent
without need for forcible stirring with a relatively strong force
as conventionally needed. Moreover, with steps (1) and (2), it is
not necessary to cool the aqueous solvent in advance, and therefore
time and labor for preparation can be eliminated. Then, in step
(3), the mixture cooled or frozen in step (2) can be gelled by
heating to produce a gelled mixture. The gel composition obtained
this time is suppressed from having non-hydrated products such as
undissolved lumps, which are caused by the galactose-partial
degradation product, mixed therein. In step (3), when the cooled
mixture is heated, it is preferable that the mixture be thawed by
heating, then forcibly stirred, and then heated, and alternatively,
it is preferable that the mixture be heated while being forcibly
stirred after it is thawed by heating. Thus, a more homogeneous gel
composition is obtainable by forcibly stirring while heating. Such
forcible stirring is preferable particularly in step (3) for the
galactose-partial degradation product having such a low
concentration in which an aqueous layer is formed, and the gel
composition can be more homogenized by being subjected to the
forcible stirring. Accordingly, the method including steps (1) to
(3) enables to easily produce the gel composition including the
galactose-partial degradation product.
[0056] When an attempt is made to disperse a polysaccharide such as
a locust bean gum in an aqueous solvent at room temperature,
undissolved lumps may occur, which causes a lot of time or the
necessity for heating to eliminate the undissolved lumps.
Therefore, the polysaccharide needs to be dispersed by, for
example, being forcibly stirred or heated after introduction into
the aqueous solvent. After the dispersion, the mixture must be
gelled by freezing and further thawing. However, if the heating is
continued after the thawing, gel transfers to sol, and hence gel
dissolves. On the other hand, the galactose-partial degradation
product is not solated even if it is continuously heated after
cooling, as mentioned above.
[0057] The galactose-partial degradation product used for the
production method of this embodiment has reverse thermal gelation
characteristics, as mentioned above, and specifically, has
characteristics where it is gelled by heating around the body
temperature. Thus, in the production method of this embodiment, the
mixture (hydrated swollen product at a comparatively low
temperature) obtained in step (2) may be applied to the skin to
carry out the gelation in step (3) through the body temperature,
for example. That is, the gel composition may be prepared when
needed. The mixture (hydrated swollen product) after cooling or
freezing in step (1) may be allowed to stand still for storage at a
low temperature of 15.degree. C. or lower until it is used in step
(3) as needed. The thus stored mixture may be moved to a mold
having a desired shape before heating in step (3), and then
subjected to step (3) in this state to thereby obtain a gel
composition as a molded article.
[0058] In step (1) of the production method for the gel composition
of this embodiment, the galactose-partial degradation product and
the aqueous solvent are preferably mixed together at 18 to
30.degree. C.
[0059] With such construction, the galactose-partial degradation
product can be dispersed in the aqueous solvent in ordinary
room-temperature environments, while further avoiding occurrence of
undissolved lumps by mixing together the galactose-partial
degradation product and the aqueous solvent at 18 to 30.degree. C.
Thus, it is possible to suppress deterioration of workability.
[0060] In step (1) of the production method for the gel composition
of this embodiment, 30 to 55% of a galactose moiety is preferably
degraded in the galactose-partial degradation product.
[0061] With such construction, by using the aforementioned
galactose-partial degradation product in which 30 to 55% of the
galactose moiety is degraded, it is possible to produce a gel
composition that is not excessively hard, while allowing it to
exhibit sufficient gelation characteristics by heating.
[0062] In step (2) of the production method for the gel composition
of this embodiment, the mixture obtained in step (1) is preferably
cooled or frozen to -25 to 10.degree. C.
[0063] With such construction, by cooling or freezing the mixture
to -25 to 10.degree. C., the galactose-partial degradation product
is easily hydrated and swollen, and excessive progress of hydration
and swelling is suppressed.
[0064] In step (1) of the production method for the gel composition
of this embodiment, 0.05 to 20 mass % of the galactose-partial
degradation product is preferably mixed in the mixture.
[0065] With such construction, it is possible to allow the mixture
to be surely gelled and allow a moderate amount of water to be
retained in the gel, thereby enabling to produce a gel composition
capable of exhibiting desired gel characteristics, when the content
of the galactose-partial degradation product is 0.05 to 20 mass
%.
[0066] In the production method for the gel composition of this
embodiment, the aqueous solvent preferably includes water or salt
aqueous solution.
[0067] The gel composition of this embodiment includes a partial
degradation product of the galactose moiety of galactoxyloglucan
obtained by the aforementioned production method for the gel
composition.
[0068] As mentioned above, according to these embodiments, there
are provided a production method that can relatively easily produce
a gel composition including a partial degradation product of the
galactose moiety of galactoxyloglucan, and a gel composition
produced by this production method.
[0069] Since the gel composition obtained by the production method
of these embodiments has characteristics where it is produced by
being gelled by heating, it is usable as a polymer material in
various industries, such as those for domestic purposes, medical
field, biomaterials, cosmetics and hence usable in various fields.
The galactose-partial degradation product used in these embodiments
is not obtained by chemical modification of a natural substance
derived galactoxyloglucan, and thus the obtained gel composition is
also harmless to the living body.
[0070] The description for the gel composition and the production
method therefor according to the embodiments was thus made, but the
present invention is not limited to the aforementioned embodiments,
and various modifications can be appropriately made within the
intended scope of the present invention. In the gel composition and
the production method therefor, additives other than the
galactose-partial degradation product and the aqueous solvent may
be appropriately added, for example.
EXAMPLES
[0071] The present invention will be hereinafter described in
detail with reference to examples but the present invention is not
limited to those examples.
Production Example 1
Production of a Partial Degradation Product of the Galactose Moiety
of Galactoxyloglucan
Purification of .beta.-galactosidase:
[0072] A 2.5% aqueous solution of a commercially available
.beta.-galactosidase having complex enzyme activity "LACTASE Y-AO"
[derived from Aspergillus oryzae, manufactured by Yakult
Pharmaceutical Industry Co., Ltd.] was subjected to 0 to 0.6 M NaCl
gradient with 0.025 M phosphate buffer (pH 7.4) of an ion exchange
chromatography [DEAE Toyopeal, manufactured by Tosoh Corporation]
to obtain eluate at a NaCl concentration of 0.2 to 0.4 M.
Furthermore, the obtained eluate was subjected to 0 to 0.6 M
ammonium sulfate gradient with 0.025 M phosphate buffer (pH 7.4) of
a hydrophobic chromatography [Butyl-Toyopeal, manufactured by Tosoh
Corporation] to obtain eluate at an ammonium sulfate concentration
of 10% or less. 60 mg of the purified enzyme was obtained from 2.5
g of a commercially available crude enzyme by these operations.
Cellulase activity and IPase (isoprimeverose generation enzyme)
activity were not found in this product.
Production of a Galactose-Partial Degradation Product:
[0073] Using the purified enzyme .beta.-galactosidase obtained
above, an aqueous solution of 1% substrate galactoxyloglucan
[GLYLOID (registered trademark), manufactured by DSP GOKYO FOOD
& CHEMICAL Co., Ltd.] was reacted at an enzyme concentration of
2.4.times.10.sup.-5 mass %, a pH of 5.6, and a temperature of
50.degree. C., and thereafter heated at 100.degree. C. for 20
minutes to stop the reaction. The obtained reaction solution was
gelled in about 15 hours after the reaction start, and, as a
result, a gelled composition was obtained. The galactose removal
ratio in the obtained gelled composition was calculated by the
method below. 1 mL of a solution with 0.15 mass % of Cellulase
Onozuka RS [manufactured by Yakult Pharmaceutical Industry Co.,
Ltd.] (50 mM acetic acid buffer solution, a pH of 4.0) was added to
7 g of an aqueous solution with 1 mass % of the gelled composition
to react at 50.degree. C. overnight. An aqueous solution with 1
mass % of galactoxyloglucan was also made to react in the same
manner and an obtained product was employed as a control. After the
reaction, the enzyme was deactivated by heating the reaction liquid
for 30 minutes at 98.degree. C. Then, a sample was subjected to a
pretreatment cartridge [IC-SP, manufactured by Tosoh Corporation]
and a membrane filter of 0.45 gm cellulose acetate to obtain
filtrate. 10 .mu.L of the obtained filtrate was applied to an amino
column of HPLC, in which acetonitrile:water=60:40 (v/v) was made to
flow at 0.6 mL/min, so that elution areas of oligosaccharides
(heptasaccharide (0 galactosemoiety), octasaccharide (1 galactose
moiety), nonasaccharide (2 galactose moieties)) of
galactoxyloglucan were detected using a refractive-index meter
equipped therein. Then, the amount of galactose per unit
(heptasaccharide) was calculated by an expression (area of
octasaccharide+(area of nonasaccharide.times.2)/(area of
heptasaccharide+area of octasaccharide+area of nonasaccharide).
When the decreasing ratio of the amount of galactose determined on
the gel composition from the amount of the galactose calculated
from the control galactoxyloglucan was designated as the galactose
removal ratio (%) and calculation was further made, the galactose
removal ratio was found to be about 45%. Then, the thus obtained
gelled composition was subjected to freeze dehydration, or was
subjected to sedimentation and filtering subsequent to the addition
of alcohol to the gelled composition, followed by drying, to obtain
a galactose-partial degradation product in powder form.
[0074] In the following experimental examples, a product produced
by heating after cooling or freezing the dispersion liquid in which
the galactose-partial degradation product has been dispersed in
water at room temperature was served as Example, and a product
produced by heating an aqueous solution (dissolved solution), in
which the galactose-partial degradation product has been dissolved
in cold water while being stirred, was served as Comparative
Example.
Experimental Example 1
(1) Production of Gel Compositions by Freezing and Heating
[0075] The galactose-partial degradation product produced in
Production Example 1 was added into 200 mL tall beakers, followed
by adding water at room temperature (25.degree. C.) thereto, to
disperse by lightly crumbling with spatula (spatel). Thus, 100 g of
the dispersion liquids were prepared with the galactose-partial
degradation product contents of 0.05 mass % (Example 1), 0.1 mass %
(Example 2), 1 mass % (Example 3), 3 mass % (Example 4), 5 mass %
(Example 5), 10 mass % (Example 6), 15 mass % (Example 7), and 20
mass % (Example 8), respectively. After the preparation of the
dispersion liquids, each 20 g of the prepared dispersion liquid was
dispensed into each of four screw cap glass vials [No. 35; content:
30 mL, manufactured by Maruemu Corporation], and the rest was
dispensed into the fifth screw cap glass vial. The amount of each
of the dispersion liquids remained and adhered to the tall beaker
after the dispensing (C) was calculated by measuring the mass of
the tall beaker after the dispensing (A), and deducting the mass of
the tall beaker itself (B) (tare), which was measured in advance,
from the mass (A) (C=A-B). The ratio of the amount of the
dispersion liquid (C) based on 100 g of the dispersion liquid
before dispensing was calculated by the expression:
(C/100).times.100. This calculation result was served as the sample
loss rate (%) of the dispersion liquid. Further, each of the
dispensed dispersion liquids was allowed to stand still for 2 hours
in a freezer [manufactured by HOSHIZAKI ELECTRIC CO., LTD., model:
HRF-180XF] set at -20.degree. C. to lower its temperature to
-20.degree. C., then left for 2 hours in this state, and then
thawed at room temperature. Thereafter, each of the dispersion
liquids was allowed to stand still in a warm bath to have its
temperature raised to 40.degree. C., and then left for 2 hours in
this state to thereby produce a gel composition.
(2) Production of Gel Compositions by Stirring and Dissolving in
Cold Water, and Heating
[0076] The galactose-partial degradation product produced in
Production Example 1 was dispersed and dissolved in water added
into a 200mL tall beaker, while being forcibly stirred under ice
cooling by a stirrer [product name: Three-One Motor] with a
propeller stirring blade attached thereto. Thus, 100 g of aqueous
solutions were prepared with the galactose-partial degradation
product contents of 0.05 mass % (Comparative Example 1), 0.1 mass %
(Comparative Example 2), 1 mass % (Comparative Example 3), 3 mass %
(Comparative Example 4), 5 mass % (Comparative Example 5), 10 mass
% (Comparative Example 6), 15 mass % (Comparative Example 7), and
20 mass % (Comparative Example 8), respectively. The amount of each
of the aqueous solutions remained and adhered to the stirrer (E)
was calculated by measuring the mass of the tall beaker containing
the aqueous solution (D) after the stirrer was taken out from the
aqueous solution, and deducting the mass of the tall beaker itself
(B) (tare), which was measured in advance, from the mass (D).
Subsequently, each 20 g of the aqueous solution remained in the
tall beaker after the stirrer was taken out was dispensed into each
of four screw cap glass vials, and the rest was dispensed into the
fifth screw cap glass vial. The amount of each of the aqueous
solutions remained and adhered to the tall beaker after the
dispensing (C') was calculated by deducting the mass of the tall
beaker itself (B) (tare), which was measured in advance, from the
mass of the tall beaker after the dispensing (A). The ratio of the
total of the amount of the aqueous solution removed as a result of
adhering to the stirrer (E) and the amount of the aqueous solution
remained and adhered to the tall beaker after the dispensing (C')
based on the original amount of 100 g was calculated by the
expression: ((E+C')/100).times.100). This calculation result was
served as the sample loss rate (%) of the aqueous solution.
Further, each of the dispensed aqueous solutions was allowed to
stand still for 2 hours in a freezer [manufactured by HOSHIZAKI
ELECTRIC CO., LTD., model: HRF-180XF] set at -20.degree. C. to
lower its temperature to -20.degree. C., then left for 2 hours in
this state, and then thawed at room temperature. Thereafter, each
of the aqueous solutions was allowed to stand still in a warm bath
to have its temperature raised to 40.degree. C., and then left for
2 hours in this state to thereby produce a gel composition.
(3) Evaluation
[0077] Evaluations mentioned below were made. The results are shown
in Table 1.
Gelled State (Gel)
[0078] The gelled states of the gel compositions dispensed in the
screw cap glass vials were visually checked. Evaluation was made,
upon inclination of the screw cap glass vial by 90 degrees, by
representing as follows: "o" when deformation of the gel was not
visually observed; ".smallcircle." when the gel was not collapsed
while deformation of the gel was observed; ".DELTA." when the gel
was collapsed; and "x" when the gel was not formed. The results are
shown in Table 1.
Entrainment of Air Bubbles in Gel Compositions (Bubble Entrainment
in Gel)
[0079] In the dispensed gel compositions, evaluation was made by
representing as follows: ".circleincircle." when bubbles in the gel
were not visually observed or a very small number of bubbles were
visually observed; "o" when a small number of bubbles were visually
observed; ".DELTA." when a large number of bubbles were visually
observed; and "x" when a very large number of bubbles were visually
observed. The results are shown in Table 1.
Easiness of Filling (Decantation)
[0080] Evaluation was made upon filling the screw cap glass vial
with a dispersion liquid or a stirred and dissolved solution by
representing as follows: ".smallcircle." filling could be made by
decantation; and "x" filling couldn't be made by decantation. The
dispersion liquid or the stirred and dissolved solution which could
not be decanted were filled using a spatel or the like. The results
are shown in Table 1.
Presence of Water Separation on Gel
[0081] Water on each of the gel compositions evaluated as
".circleincircle." and ".smallcircle." in the aforementioned
evaluation for the gelled state was transferred from the screw cap
glass vial to the plastic cup whose mass was measured in advance to
measure the mass thereof. The mass of water transferred to the
plastic cup was calculated by deducting the mass of the plastic cup
(tare) from the obtained total mass. Further, water remained and
adhered to the inner wall of the screw cap glass vial was wiped off
with the Kimwipes [product name: Wiper S-200; manufactured by
Nippon Paper Crecia Co., Ltd.] whose mass was measured in advance
to measure the mass thereof. The mass of the absorbed water was
measured by deducting the mass of Kimwipes (tare) from the obtained
mass. Then, the total of the mass of water transferred to the
plastic cup and the mass of water absorbed by Kimwipes was
calculated as the amount of separated water F (g), and the ratio
(%) of the amount of separated water F based on the mass (20 g) of
the dispersion liquid or the aqueous solution dispensed in the
screw cap glass vial was calculated as the water separation ratio
(%). Further, the mass of the gel composition was calculated by
deducting the amount of the separated water F (g) from the mass of
the dispensed dispersion liquid or aqueous solution (20 g) (mass
G=20-F). The concentration of the galactose-partial degradation
product of this gel composition was calculated, based on the mass
(20 g) of the dispersion liquid or the aqueous solution containing
the galactose-partial degradation product with the concentration H
before removing the separated water, by the expression:
(20/(20-F).times.H). The obtained value was served as the
concentration of the produced gel (mass %). Further, the
concentration rate (magnification) was calculated by dividing the
obtained concentration of the produced gel by the concentration I
(mass %) of the dispersion liquid or the aqueous solution before
removing the separated water (concentration rate=(concentration of
the produced gel)/I). The results are shown in Table 1. The amount
of separated water in the gel composition evaluated as ".DELTA." in
the above evaluation on the gelled state could not be measured
because the content collapsed when the screw cup glass vial
containing it was tilted. Since the water separation was not found
in the gel composition (Examples 5 to 8, Comparative Examples 5 to
8), in which the concentration of the galactose-partial degradation
product was 5 mass % or more, the concentration after dispensing
the produced gel composition was the same as that of the dispersion
liquid or the aqueous solution before removing the separated water.
That is, the concentration rate was 1 time.
[0082] As shown in Table 1, it was found that the gel composition
obtained from the dispersion liquids including 0.05 to 20 mass % of
the galactose-partial degradation product based on the total mass
of the composition (Examples 1 to 8) exhibits good gel formation.
When comparing the composition obtained from the aqueous solutions
(stirred and dissolved solutions) containing less than 1 mass % of
the galactose-partial degradation product (Comparative Examples 1
and 2) with the composition obtained from the dispersion liquids
with the same concentration (Examples 1 and 2), water separation
did not occur in the aqueous solution (Comparative Examples). It
was found from this that the galactose-partial degradation product
was not concentrated in the aqueous solution (Comparative
Examples), and thus the gel formation was not confirmed. On the
other hand, a water layer was separated on the upper side of the
dispersion liquid (Examples), and thereby the galactose-partial
degradation product was concentrated therebelow, which resulted in
good gel formation. When comparing the composition obtained from
the aqueous solutions (stirred and dissolved solutions) containing
1 mass % of the galactose-partial degradation product (Comparative
Example 3) with the composition obtained from the dispersion
liquids with the same concentration (Example 3), water separation
did not occur in the aqueous solution (Comparative Examples). It
was found from this that the galactose-partial degradation product
was not sufficiently concentrated in the aqueous solutions
(Comparative Example), and thus only a weak gel having a low
strength was produced. On the other hand, a water layer was
separated on the upper side of the dispersion liquid (Example), and
thereby the galactose-partial degradation product was concentrated
therebelow, which resulted in producing a good gel having a high
strength.
[0083] As to the bubble entrainment in the gel, it was found that
the compositions (Examples 3 to 5) obtained from the dispersion
liquids including 0.05 to 5 mass % of the galactose-partial
degradation product therewith had smaller bubbles entrained therein
and better appearance than the gels obtained from the aqueous
solutions with the same concentration (stirred and dissolved
solutions, Comparative Examples 3 to 5).
[0084] The dispersion liquid (Examples) could be filled in the
screw cap vial by decantation until it reaches 10 mass %, while the
aqueous solution (Comparative Examples) could not be filled therein
any more by decantation when it reaches 5 mass % or more, since the
aqueous solution had excessively high viscosity.
[0085] The total sample loss rate (loss, sample loss rate due to
the adhesion to the container) when having filled the dispersion
liquid was much smaller than the total sample loss rate (loss,
sample loss rate due to the adhesion to the container and the
stirrer) when having filled the aqueous solution.
[0086] Even if water separation occurs on the upper side of the gel
in the dispersion liquid, such water separation can be suppressed
or adjusted using a shallow container enabling a small depth of the
dispersion liquid, when heating. Specifically, it is possible to
adjust the concentration of the produced gel of the gel composition
not only by changing the original amount of the galactose-partial
degradation product to be added (concentration) but also by, for
example, changing the depth of the dispersion liquid.
[0087] Compositions (Comparative Examples 9 and 10) were produced
in the same manner as the aforementioned Examples using
galactoxyloglucan [manufactured by DSP GOKYO FOOD & CHEMICAL
Co., Ltd., GLYLOID (registered trademark)] in which a galactose
moiety is not removed, the obtained dispersion liquid became
viscous body containing large amounts of undissolved lumps and was
not gelled even by heating.
TABLE-US-00001 TABLE 1 Amount added Cooling Bubble Sample Presence
or absence of (mass %) temperature (.degree. C.) Gelled state
entrainment in gel loss rate (%) Decantation Water separation on
gel Ex. 1 0.05 -20 .DELTA. .circleincircle. 0.1 .largecircle.
presence Com. Ex. 1 0.05 -- X -- 0.02 .largecircle. -- Ex. 2 0.1
-20 .circleincircle. .circleincircle. 0.1 .largecircle. presence
Com. Ex. 2 0.1 -- X -- 0.1 .largecircle. -- Ex. 3 1 -20
.circleincircle. .circleincircle. 0.3 .largecircle. presence Com.
Ex. 3 1 -- .DELTA. .DELTA. 2.7 .largecircle. absence Ex. 4 3 -20
.circleincircle. .circleincircle. 0.6 .largecircle. presence Com.
Ex. 4 3 -- .circleincircle. X 7.4 .largecircle. absence Ex. 5 5 -20
.circleincircle. .circleincircle. 1.1 .largecircle. absence Com.
Ex. 5 5 -- .circleincircle. X 17.1 X absence Ex. 6 10 -20
.circleincircle. .largecircle. 3.7 .largecircle. absence Com. Ex. 6
10 -- .circleincircle. X 8.9 X absence Ex. 7 15 -20
.circleincircle. .DELTA. 1.6 X absence Com. Ex. 7 15 --
.circleincircle. X 6.8 X absence Ex. 8 20 -20 .circleincircle.
.DELTA. 0.5 X absence Com. Ex. 8 20 -- .circleincircle. X 2.8 X
absence Com. Ex. 9 3 -20 X -- -- -- -- Com. Ex. 10 5 -20 X -- -- --
-- Amount of Amount of Concentration of produced Concentration rate
separated water (g) separated water (%) gel (mass %)
(magnification) Ex. 1 unmeasurable -- -- -- Com. Ex. 1 -- -- -- --
Ex. 2 18.4 92 1.3 13 Com. Ex. 2 -- -- -- -- Ex. 3 11.5 57 2.4 2.4
Com. Ex. 3 0 0 1 1 Ex. 4 3.3 16 3.6 1.2 Com. Ex. 4 0 0 3 1 Ex. 5 0
0 5 1 Com. Ex. 5 0 0 5 1 Ex. 6 0 0 10 1 Com. Ex. 6 0 0 10 1 Ex. 7 0
0 15 1 Com. Ex. 7 0 0 15 1 Ex. 8 0 0 20 1 Com. Ex. 8 0 0 20 1 Com.
Ex. 9 -- -- -- -- Com. Ex. 10 -- -- -- --
Experimental Example 2
Cooling Temperature and Gel Formation of Dispersion Liquid of
Galactose-Partial Degradation Product
[0088] 0.6g (3 mass %) and 1.0 g (5 mass %) of the
galactose-partial degradation product produced in Production
Example 1 were added into screw cap glass vials, followed by adding
water at room temperature thereto, to obtain a total amount of 20 g
of each of dispersion liquids of the galactose-partial degradation
product. Each of the dispersion liquids was cooled at 12.degree. C.
(Examples 9 and 10), 11.degree. C. (Examples 11 and 12), 10.degree.
C. (Examples 13 and 14), 8.degree. C. (Examples 15 and 16),
6.degree. C. (Examples 17 and 18), 4.degree. C. (Examples 19 and
20), 3.degree. C. (Examples 21 and 22), 2.degree. C. (Examples 23
and 24), 1.degree. C. (Examples 25 and 26), 0.degree. C. (Examples
27 and 28), -5.degree. C. (Examples 29 and 30), -10.degree. C.
(Examples 31 and 32), -15.degree. C. (Examples 33 and 34), and
-20.degree. C. (Examples 35 and 36) using a thermostatic device
[manufactured by ESPEC CORP., model type: PR-2KP], and left in this
state for 2 hours to produce a hydrated swollen solution
(dispersion liquid). Each sample after cooling was checked whether
the dispersion liquid was frozen or not by visual observation and
touching with spatel. The frozen dispersion liquid was left
standing at room temperature to be thawed. The dispensed
composition was raised to a temperature of 40.degree. C. after the
thawing, and left in this state for 2 hours, and thereafter the
degree of gelation, the water separation on the upper side of the
gel, and the bubble entrainment in the gel were observed by the
aforementioned method. The results are shown in Table 2 and Table
3.
[0089] As shown in Tables 2 and 3, when the dispersion liquid was
cooled at a temperature of 12.degree. C. (Examples 9 and 10),
gelation was not confirmed in both of the samples of 3 mass % and 5
mass %. When cooled at 11.degree. C. (Examples 11 and 12), gelation
was confirmed in the sample of 5 mass %. When cooled or frozen at
10.degree. C. or lower and -20.degree. C. or higher (Examples 13 to
36), gelation was confirmed in any samples of 3 mass % and 5 mass
%. When cooling or freezing at 10.degree. C. or less and
-20.degree. C. or more (Examples 13 to 36), gelation was confirmed
in both of the samples of 3 mass % and 5 mass %. When cooled or
frozen at 10.degree. C. or lower and -20.degree. C. or higher,
water separation was observed on the upper side of the sample of 3
mass % after heating. Further, it was found that whether the
dispersion liquid was frozen or not does not influence on the
gelation performance. The amount of separated water observed on the
upper side of the gel was constant regardless of the cooling
temperature.
TABLE-US-00002 TABLE 2 Additive Cooling amount temperature Bubble
(mass %) (.degree. C.) Freezing Gel entrainment in gel Ex. 9 3 12
Not frozen X -- Ex. 10 5 12 Not frozen X -- Ex. 11 3 11 Not frozen
X -- Ex. 12 5 11 Not frozen .DELTA. -- Ex. 13 3 10 Not frozen
.DELTA. .circleincircle. Ex. 14 5 10 Not frozen .DELTA.
.circleincircle. Ex. 15 3 8 Not frozen .DELTA. .circleincircle. Ex.
16 5 8 Not frozen .largecircle. .circleincircle. Ex. 17 3 6 Not
frozen .largecircle. .circleincircle. Ex. 18 5 6 Not frozen
.circleincircle. .circleincircle. Ex. 19 3 4 Not frozen
.circleincircle. .circleincircle. Ex. 20 5 4 Not frozen
.circleincircle. .circleincircle. Ex. 21 3 3 Not frozen
.circleincircle. .circleincircle. Ex. 22 5 3 Not frozen
.circleincircle. .circleincircle.
TABLE-US-00003 TABLE 3 Additive Cooling Bubble amount temperature
Whether entrainment (mass %) (.degree. C.) Frozen or not Gel in gel
Ex. 23 3 2 Not frozen .circleincircle. .circleincircle. Ex. 24 5 2
Not frozen .circleincircle. .circleincircle. Ex. 25 3 1 Not frozen
.circleincircle. .circleincircle. Ex. 26 5 1 Not frozen
.circleincircle. .circleincircle. Ex. 27 3 0 Not frozen
.circleincircle. .circleincircle. Ex. 28 5 0 Not frozen
.circleincircle. .circleincircle. Ex. 29 3 -5 Not frozen
.circleincircle. .circleincircle. Ex. 30 5 -5 Not frozen
.circleincircle. .circleincircle. Ex. 31 3 -10 Partly frozen
.circleincircle. .circleincircle. Ex. 32 5 -10 Not frozen
.circleincircle. .circleincircle. Ex. 33 3 -15 Frozen
.circleincircle. .circleincircle. Ex. 34 5 -15 Frozen
.circleincircle. .circleincircle. Ex. 35 3 -20 Frozen
.circleincircle. .circleincircle. Ex. 36 5 -20 Frozen
.circleincircle. .circleincircle.
Experimental Example 3
Heat Resistance of Gel
[0090] 1.5 g (3 mass %) and 2.5 g (5 mass %) of the
galactose-partial degradation product produced in Production
Example 1 were added into snap cap glass vials [No. 50; content: 60
mL, manufactured by Maruemu Corporation], followed by adding water
at room temperature thereto, to obtain a total amount of 50 g of
each of dispersion liquids of the galactose-partial degradation
product. Each of the dispersion liquids was allowed to stand still
for 2 hours in a freezer [manufactured by HOSHIZAKI ELECTRIC CO.,
LTD., model: HRF-180XF] set at -20.degree. C. to have its
temperature lowered to -20.degree. C., then left for 2 hours in
this state, and then thawed at room temperature, allowed to have
the temperature raised to 40.degree. C. in a warm bath, and then
left for 2 hours in this state to thereby produce a composition.
Thereafter, the snap cap glass vials were covered from above with
aluminum foil, placed on a stainless tray, and allowed to stand
still for 1 hour in the oven [model type: WFO-450ND; manufactured
by Tokyo Rikakikai Co., Ltd.] set at 110.degree. C. After the
standing still, the vials were taken out and tilted by 90 degrees.
Visual observation for the strength of the gel revealed that none
of the gels collapsed. On the other hand, water was added into snap
cap glass vials, while being forcibly stirred under ice cooling by
a stirrer [product name: Three-One Motor] with a propeller stirring
blade attached thereto, and 1.5 g (3 mass %) and 2.5 g (5 mass %)
of the galactose-partial degradation product produced in Production
Example 1 were added thereto to be dispersed or dissolved, to
obtain a total amount of 50 g of each of aqueous solutions of the
galactose-partial degradation product. Each of the aqueous solution
was allowed to have its temperature lowered to -20.degree. C., and
then allowed to have its temperature raised to 40.degree. C., and
left in this state, to thereby produce a gel composition in the
same manner as mentioned above. Thereafter, visual observation for
the strength of the gel was performed in the same manner as the
above, which revealed that when this dispersion liquid was heated,
expansion of bubbles are caused, which resulted in large
deformation in the gel and hence caused the gel to have its shape
collapsed (broken into pieces separated from each other), because
the aqueous solution included a considerable number of bubbles.
Experimental Example 4
Water Resistance of Gel
[0091] 1.0 g (5 mass %) of the galactose-partial degradation
product produced in Production Example 1 was added into a plastic
cup [EI-90, product name: PROMAX, content: 90 mL, manufactured by
ASAHIKASEI PAX CORPORATION], followed by adding water at room
temperature thereto, to obtain a total amount of 20 g of a
dispersion liquid of the galactose-partial degradation product. The
dispersion liquid was allowed to stand still for 2 hours in a
freezer [manufactured by HOSHIZAKI ELECTRIC CO., LTD., model:
HRF-180XF] set at -20.degree. C. to have its temperature lowered to
-20.degree. C., then left for 2 hours in this state, then thawed at
room temperature, then heated in a warm bath to have its
temperature raised to 40.degree. C., and left for 2 hours in this
state. Thereby, the composition was produced. Thereafter, three gel
compositions (gel compositions produced in the same manner using
three plastic cups) were taken out from the plastic cups and
introduced into a 500 mL glass beaker with about 300 mL of water
contained therein, followed by further adding water thereto to have
a total amount of about 400 mL. On the other hand, three gel
compositions (gel compositions produced in the same manner using
three plastic cups) were taken out from the plastic cups, placed on
stainless trays, and covered with wraps to be served as controls.
Gels in water and gels on the stainless trays were allowed to stand
still in an incubator set at a temperature of 25.degree. C. for 24
hours. After the standing still for 24 hours, the gels were taken
out, visual observation was performed on the shape of the gel,
which revealed that the gels in water did not collapse.
Experimental Example 5
Stability of Gel
[0092] 1.0 g and 2.0 g of the galactose-partial degradation product
were added into glass vials, followed by adding 0.6 g of
HYDROLITE-5 [manufactured by Symrise AG] as preservative thereto,
and then adding water at room temperature thereto, to prepare a
total amount of 20 g of each of dispersion liquids respectively
including 5 mass % and 10 mass % of the galactose-partial
degradation product. Each of the dispersion liquids was allowed to
have its temperature lowered and raised in the same manner as the
above to produce a composition. The obtained compositions were left
for 3 months at temperatures of 4.degree. C., 25.degree. C., and
40.degree. C. to observe water separation. The results are shown in
Table 4. The evaluation on whether water was separated or not was
made according to the following evaluation criteria.
[0093] Separated: Partial water separation can be observed.
[0094] Not separated: Almost no water separation can be
observed.
[0095] As shown in Table 4, it was revealed that water separation
did not occur when stored at the temperature of 4.degree. C. and
25.degree. C. until the lapse of 90 days in any compositions
obtained using the dispersion liquids with 5 mass % and 10 mass %
of the galactose-partial degradation product. It was also revealed
that, when stored at 40.degree. C., significant water separation
did not occur until the lapse of 14 days in the dispersion liquid
with 10 mass % of the galactose-partial degradation product, and
until the lapse of 60 days in the dispersion liquid with 5 mass %
of the galactose-partial degradation product.
TABLE-US-00004 TABLE 4 Presence or absence of water Storage period
Amount added separation in each storage temperature (day) (%)
4.degree. C. 25.degree. C. 40.degree. C. 7 5 absence absence
absence 10 absence absence absence 14 5 absence absence absence 10
absence absence absence 30 5 absence absence absence 10 absence
absence presence 60 5 absence absence absence 10 absence absence
presence 90 5 absence absence presence 10 absence absence
presence
Test Example 1
Viscosity Change of Galactoxyloglucan and Galactose-partial
Degradation Product
[0096] Water at 25.degree. C. was added to galactoxyloglucan
[manufactured by DSP GOKYO FOOD & CHEMICAL Co., Ltd., GLYLOID
(registered trademark)], in which a galactose moiety is not
removed, and the galactose-partial degradation product to allow
them to disperse in water, to thereby obtain dispersion liquids
including 1.5 mass % and 5 mass % of the respective components.
Thereafter, increase in viscosity of each of the dispersion liquids
was measured by a rapid visco analyser [model: RVA-4; manufactured
by Newport Scientific Inc.] for 60 minutes. The increase in
viscosity with time represents that dissolution is in progress. As
shown in FIG. 1, the viscosity greatly increased immediately after
the dispersion of galactoxyloglucan, while the viscosity did not
change in the dispersion of the galactose-partial degradation
product. It was found from the above results that the dispersion
liquid including the galactose-partial degradation product is
easier to handle than the dispersion liquid including
galactoxyloglucan, in which a galactose moiety is not removed,
since the galactose-partial degradation product hardly progresses
from the hydrated and swollen state to the dissolution state after
dispersion and hence does not increase in viscosity.
* * * * *